Instrument's Characteristics
The reference for the instrument characteristics is the XSHOOTER User Manual.
Spectrograph characteristics
| Arm | λ-range | N. of orders | scale |
AB limit |
|---|---|---|---|---|
| (nm) | (''/pix) | (mag) | ||
| UVB | 300-560 | 12 | 0.161 | 21.2 (at 356.1 nm, ord N.21) 21.7 (at 438.8 nm, ord N.17) |
| VIS | 550-1020 | 15 | 0.158 | 20.9 (at 653.8 nm, ord N.35) 20.8 (at 777.6 nm, ord N.21) |
| NIR | 1020-2480 | 16 | 0.248 | 21.0 (at 1245.2 nm, ord N.21) 20.6 (at 1634.4 nm, ord N.16) 18.7 (at 2179.2 nm, ord N.12) |
Spectrograph resolution, for the NIR arm with the new slits wheel
| arm | slit width [1] | R=(λ/Δλ) | sampling | arm | slit width | R=(λ/Δλ) | sampling | arm | slit width | R=(λ/Δλ) | sampling |
|---|---|---|---|---|---|---|---|---|---|---|---|
| (") | (pix/FWHM) | (") | (pix/FWHM) | (") | (pix/FWHM) | ||||||
| UVB | 0.5 | 9700 | 3.1 | VIS | 0.4 | 18400 | 2.5 | NIR | 0.4 | 11600 | 1.6 |
| 0.8 | 6700 | 5.0 | 0.7 | 11400 | 4.4 | 0.6 | 8100 | 2.5 | |||
| 0.6JH [2] | 8100 | 2.5 | |||||||||
| 1.0 | 5400 | 6.2 | 0.9 | 8900 | 5.7 | 0.9 | 5600 | 3.7 | |||
| 0.9JH [2] | 5600 | 3.6 | |||||||||
| 1.3 | 4100 | 8.1 | 1.2 | 6500 | 7.6 | 1.2 | 4300 | 4.8 | |||
| 1.6 | 3200 | 9.9 | 1.5 | 5000 | 9.5 | ||||||
| UVB | IFU [3] | 8600 | 3.9 | VIS | IFU [3] | 13500 | 3.7 | NIR | IFU [3] | 8300 | 2.4 |
[1] All slits have a fixed length of 11''. [2] The 0.6"JH and 0.9"JH are the two new slits with the K-band blocking filter. [3] The IFU FoV is 4''x1.8 '' which is re-sampled in a 0.6'' x 12 '' slit in the spectrographs (not offerred anymore since P111).
Detector characteristics
| arm | detector | readout mode | gain | RON | readout time | saturation |
|---|---|---|---|---|---|---|
| (e-/ADU) | (e-) | (s) | (ADU) | |||
| UVB | 4k x 2k E2V CCD44-82 | 100,1x1,hg | 0.63 | 2.4 | 68 |
65000 |
| 100,1x2,hg | 0.63 | 2.4 | 34 | |||
| 100,2x2,hg | 0.63 | 2.4 | 17 |
|||
| 400,1x1,lg | 1.83 | 4.6 | 16 | |||
| 400,1x2,lg | 1.83 | 4.6 | 8 |
|||
| 400,1x2,lg | 1.83 | 4.6 | 4 |
|||
| VIS | 4k x 2k MIT/LL CCID 20 | 100,1x1,hg | 0.64 | 3.4 | 89 |
65000 |
| 100,1x2,hg | 0.64 | 3.4 | 45 | |||
| 100,2x2,hg | 0.64 | 3.4 | 23 | |||
| 400,1x1,lg | 1.64 | 6.6 | 21 | |||
| 400,1x2,lg | 1.64 | 6.6 | 11 | |||
| 400,2x2,lg | 1.64 | 6. | 6 |
|||
| NIR | 2k x 2k Hawaii 2RG | NDR | 2.29 | 8-25[1] | "1.46" |
45000 |
| AGCCD | 562x528 | fast | 1.29 | 4.14 | "1.2" | 65535 |
[1] The RON depends on the DIT. For DIT > 300s, the RON is ~8 e-.
Old spectrograph resolution [1]
arm |
slit width [2] | R=(λ/Δλ) | sampling | arm | slit width | R=(λ/Δλ) | sampling | arm | slit width | R=(λ/Δλ) | sampling |
|---|---|---|---|---|---|---|---|---|---|---|---|
| ('') | (pix/FWHM) | (") | (pix/FWHM) | (") | (pix/FWHM) | ||||||
| UVB | 0.5 | 9100 | 3.5 | VIS | 0.4 | 17400 | 3.0 | NIR | 0.4 | 11300 | 2.0 |
| 0.8 | 6200 | 5.2 | 0.7 | 11000 | 4.8 | 0.6 | 8100 | 2.8 | |||
| 1.0 | 5100 | 6.3 | 0.9 | 8800 | 6.0 | 0.9 | 5600 | 4.0 | |||
| 1.3 | 4000 | 8.1 | 1.2 | 6700 | 7.9 | 1.2 | 4300 | 5.3 | |||
| 1.6 | 3300 | 9.9 | 1.5 | 5400 | 9.7 | 1.5 | 3500 | 6.6 | |||
| UVB | IFU [3] | 7900 | 4.1 | VIS | IFU [3] | 12600 | 4.2 | NIR | IFU [3] | 8100 | 2.8 |
[1] The values in this table have been measured for two slits in each arm and interpolated with a model for the others. [2] All slits have a fixed length of 11''. [3] The IFU FoV is 4''x1.8 '' which is re-sampled in a 0.6''x12 '' slit in the spectrographs.